1. Field of the Invention
The invention relates to a circular connector for industrial applications having a socket part which has a handle body with a cylindrical contact carrier that can be inserted into a sleeve-shaped receiving region which is provided on a plug part made as a mating part.
2. Description of Related Art
German Patent DE 10 2005 056 563 B3 discloses a circular connector with a vibration resistance. Connectors without vibration resistance are also used in various branches of industry. They ordinarily are formed of an elastic handle body and a contact carrier with cable set. The cable set is positioned in the longitudinal direction and at 90° to the plug-in direction. The handle body encompasses both the contact carrier and also the cable set in sections.
Designs are also known in which the user can connect the cable itself to a plug-in system. Here, the handle body is made as a housing with internal contact terminals.
A union nut with an internal thread is designed for connection to a corresponding mating part which can be provided, for example, on a sensor of industrial automation technology. Two versions of the connector are possible, male (plug) and female (socket).
In the operating state, the sensors are securely connected to a control/evaluation unit via the respective cable set. Often, in the control/evaluation units, not only are the sensor signals evaluated, but the voltage supply of the sensors is also made available from there.
Often, these connectors are used in very rough industrial environments. One area of application of these connectors is the food domain where strict hygiene regulations apply to the systems. Generally acid-containing or basic detergent/disinfection agents are used to clean them.
Another area of application is the production/tool domain (non-food) where the systems must meet other requirements. For connectors in this domain, especially coolant or lubricant resistance is of great importance.
In both applications (food/non-food) high pressure/steam jet cleaning methods can also be used.
Altogether, the penetration of liquids into the inner region of an installed connector can lead to corrosion on conductive components within the connector (for example, on the contact carrier).
A failure of a connector, for example, due to corrosion, depending on the application, can lead to shutdown of the entire system under certain circumstances, and thus, can cause major costs.
For small connectors, i.e., ≦M8, there is an industrial standard DIN EN 61076-2-104 which for M8 circular connectors among others specifies the dimensioning of the plug parts with the corresponding tolerances.
O-rings are often used for sealing in these connectors, which are smaller than the M12 plugs. However, since there is no defined support or stop surface for the plugs, the O-ring can be pinched or pushed out of its intended position when the screwed connection is established because there must be a certain axial play between the connector and the mating part. In both cases the sealing action can be adversely affected.
The O-rings are pinched to an intensified degree when deviations from the standard occur in the production of the connectors or their mating parts, as cannot be precluded in manufacturers around the world.
Nor can it be precluded that the O-ring will stick on the mating part and therefore will be lost unnoticed by the user when the plug and socket connection is broken on the actual connector. When another plug and socket connection is established, the sealing element is then missing and liquid can very easily travel into the inner region of the connector. Altogether, reliable sealing in connectors cannot be ensured via an O-ring as the sealing element.